Starship Asterisk*

This is not a new pneomenon. It was studied - at least theoretically - by Kelvin in the 19th century and has been observed in laboratories, in Earth's weather, and in other contexts. See: http://chaos.aip.org/resource/1/chaoeh/v12/i3/p574_s1?isAuthorized=no http://journals.ametsoc.org/doi/abs/10.117...

It's not the first time that I've noticed common English errors in the APOD text. It seems literacy has long been considered irrelevant to scientists and engineers. But as for the current discussion the matter is very simple: it less of one thing and fewer of a number of things.

Most galaxies in the image - not all of course - seem roughly positioned along a line: I immediately thought of a sort of ecliptic. Might the "walls" of galaxies be due to some gravitational effect making objects tend to move around a common plane? Concentrations of positive mass (i.e., h...

Most galaxies in the image - not all of course - seem roughly positioned along a line: I immediately thought of a sort of ecliptic. Might the "walls" of galaxies be due to some gravitational effect making objects tend to move around a common plane?

Technical question about APOD and Vimeo: around 3 a.m. EDT I went to APOD, clicked on the Vimeo start arrow, and waited. The music came on but the screen remained black. Went back around 11:15 a.m. EDT and this time music and image were both fine. Was there a glitch that was repaired between those t...

The red spiral arms (said to contain stellar nurseries) seem to be evenly spaced. There are three and they seem roughly 1/3rd of a circle apart. Is this so? I meant three main red arms. I know it's not a perfectly neat picture, but the trend seems clear enough. And besides whether it's true for M10...

The red spiral arms (said to contain stellar nurseries) seem to be evenly spaced. There are three and they seem roughly 1/3rd of a circle apart. Is this so?

the reddish jets of hydrogen gas appear to be falling into galaxy core above and below plain of galaxy. what this may mean is that more than one spiral orientation is involved - secondary spiral structures consisting of molecular gas and dust can form on a different plain due to intense gravitation...

bystander wrote:

Axel wrote:You are surprised astrologers use astronomy?

I am surprised present day astrologers even know what astronomy is.

Think again.
Axel Harvey
Astrologer

Is the inflection point at the top of the curve the position of Venus at its maximum elongation from the Sun, around 9 June 2007? Nothing else seems to make sense considering the time span involved. Duffing oscillator - a brilliant analogical flash! Thanks for that. Mr Stevenson, why the "Alas&...

Why is the Vernal Point between the two planets? That certainly is not the case today or on the coming autumn equinox. I have doubts about the relative position of the three points for any moment this year or next - unless there's something about the orientation of the photo I don't get. Because th...

Why is the Vernal Point between the two planets? That certainly is not the case today or on the coming autumn equinox. I have doubts about the relative position of the three points for any moment this year or next - unless there's something about the orientation of the photo I don't get.

Scroll right as far as you can. Look at the dark dust lane. Can you find an obvious blue star inside this dust lane, close to the top of the picture? It should be the topmost blue star that you can see, as long as you remember to scroll right as far as you can. Now you are quite close to the center...

Thank you for your detailed reply, Ann. Yes, I know about dust lanes - I was just disoriented by that marvellous picture. So the actual galactic centre is near that spot in the dust lane, roughly halfway up the height of the image, where a blue star is approximately in line with a pink nebula or gas...

But pardon an ignoramus here - is "the multicolored... center of our Galaxy" the area featuring five very bright stars and magenta, beige, and blue clouds, the equivalent of slighly less than one picture height from the left? And if so, what part of the region is most closely in line with...

A 50-degree field like this is indeed amazing. But pardon an ignoramus here - is "the multicolored... center of our Galaxy" the area featuring five very bright stars and magenta, beige, and blue clouds, the equivalent of slighly less than one picture height from the left? And if so, what p...

I should add that I also checked Mercury's position in the astrometric J2000 and mean J2000 systems and there is no appreciable difference in retrogradation dates from those I posted above.

The multiple exposures in the photo were taken at intervals of one solar day, not one sidereal day. Retrograde motion is ordinarily defined with respect to the stars, not the sun. Umm... That should not make any difference. The tables from which I get my information are based on Terrestrial Time (a...

Why does Mercury appear to change direction on the 11th of April in this picture when it went retrograde in longitude and right ascension, and changed direction in declination, around the 17th-18th iirc? The multiple exposures in the photo were taken at intervals of one solar day, not one sidereal ...

Why does Mercury appear to change direction on the 11th of April in this picture when it went retrograde in longitude and right ascension, and changed direction in declination, around the 17th-18th iirc?

htom wrote:Planets in such a place may not have anything like an orbit at all.

And therefore no Kepler or Newton, even if the temperature is stable.

ref- what formed this the answer is gravity and time nothing else. what would life / the view be like living on a planet in that cluster? Like several posters I am curious too - what would it be like if I looked at the night sky from a planet with an Earth-like atmosphere abouy 50 l.y. from the clu...

Freefall74 wrote:Is this NGC 981 or 918???

Ha! I was just going to ask the same question. I think it's 918.

The image is indeed beautiful with its wispy clouds and the elegant NGC 981. But gawd! I'm tired of that downer metaphor "death explosion" or "death star". Those explosions are spilling out the stuff of life - oxygen, carbon, iron - which gave birth to us and who knows what other...

Thanks to Qev and Chris for their responses to my OP. Now this is the way I see it. If there is a reference plane parallel to the image plane and located between us (i.e. the image on our screens) and the galactic centre, and if a person floating near the galactic centre is looking towards us with h...